Portion of a mask elbow



FIG. 1 is a perspective illustration of a portion of a mask elbow according to our design;

FIG. 2 is different perspective view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a right side view thereof with the left side view being a mirror image thereof;

FIG. 6 is a front view thereof; and,

FIG. 7 is a rear view thereof.

Where included, broken lines showing environment or structure are for illustrative purposes only and form no part of the claimed design. 

The ornamental design of a portion of a mask elbow, as shown and described. 